I started to reply to this the other day, but never quite finished the post (for what it's worth, I understood your question - it was clear to me, at least - but didn't have a good answer in hand). I haven't used the 1070 and don't recall previous discussions well enough to know quite how the logic works. I do recall some discussions at some point in which re-directed bass went to the sub if the sub was enabled, even if the mains were large. If that were the case for the 1070, I'd expect the "LFE" setting to send LFE and the RDB from small speakers to the sub. (The "L/R+Sub" scheme would then to all of that plus a copy of re-directed bass from the mains.) If nobody else around here has an actual answer for you (instead of my random theorizing), you might call Outlaw or contact them online to get the official word...